John Gill Commentary Psalms 129:4

"Jehovah is righteous: He hath cut asunder the cords of the wicked." — Psalms 129:4 (ASV)

The Lord [is] righteous

Or gracious and merciful; hence acts of mercy are called righteousness in the Hebrew language; the Lord has compassion on his people under their afflictions, and delivers them; or is faithful to his promises of salvation to them, and just and righteous to render tribulation to them that trouble them, and take vengeance upon them;

he has cut asunder the cords of the wicked :

alluding to the cords with which the plough is fastened to the oxen, which being cut, they cannot go on ploughing; or to the cords of whips, which when, cut cannot be used to any purpose: it designs the breaking of the confederacies of wicked men against the people of God; the confounding their counsels and schemes, and disappointing their devices; so that they cannot perform their enterprises, or carry their designs into execution, or go on with and finish their intentions. The Targum renders it, ``the chains of the wicked;'' see (Isaiah 5:18) .